In the past, hypochlorite ions or chlorine have been employed as oxidants and deodorants, bleaching agents and bacteriastats. However, these agents are useless in hydrocarbon and halogenated hydrocarbon fluids in which they are insoluble.
Further, various forms of activated carbon have been used to remove small quantities of liquid or gaseous substances from fluid media (liquids or gases). However, the available adsorption sites are eventually saturated resulting in depletion of the media.
While nitrogen trichloride has long been known as a strong oxidizing agent, its use has been restricted by its toxic and explosive characteristics. This volatile lipophilic liquid is almost insoluble in aqueous solutions and therefore sinks to the bottom of aqueous solutions to form concentrated pools of extremely corrosive and explosive liquid; gaseous nitrogen trichloride, on the other hand, rises to mix with the air above its solution forming an explosive and toxic mixture. However, in hydrocarbon or halogenated hydrocarbon fluids, nitrogen trichloride is quite soluble and rapidly becomes dispersed throughout the fluid where it is dangerous only when in concentration of over 12% and is exposed to a source of ignition. It can be used as an oxidizing agent for solids or liquids suspended in hydrocarbon or halogenated hydrocarbon fluids if the following conditions are met:
A. the addition method is such that the NCl.sub. 3 concentration never exceeds 10% but is always high enough (often less than 2 mg/l to meet the oxidizing requirements of the contaminant being oxidized, bleached or deactivated. PA1 B. the nitrogen trichloride can be intimately united with the contaminant being bleached by adsorbing it and the contaminant on an adsorption medium .